Sony 10-18mm works on Full Frame?! Am I crazy?!

So I just bought a Sony a6500 and the Sony E Mount 10-18mm UWA lens. I read that it would work on a full frame sensor between 12-14mm with no vignette. But to my surprise I put it on my a9 and it appears to work throughout the full focal range with no problem. There has to be a catch here right? Both images taken at 10mm with no cropping done. Second image my face was about just a few inches from the front lens element.

Found out that the a9 automatically registers when there is a crop lens on it and switches to crop mode. That's how it was working through the full FL with no vignette. Pretty crazy tech.

Jarvis Creative Studios wrote in post #18451545
Found out that the a9 automatically registers when there is a crop lens on it and switches to crop mode. That's how it was working through the full FL with no vignette. Pretty crazy tech.

Yes, this is a setting on the camera menu.

Jarvis Creative Studios wrote in post #18451545
Found out that the a9 automatically registers when there is a crop lens on it and switches to crop mode. That's how it was working through the full FL with no vignette. Pretty crazy tech.

i have been toying with the idea of carrying a 10-18 for family travel photography paired with an FF body. Substantial benefit on weight but still have an 18MP file to work with.

i saw in the sony alpha camera group in facebook how the 55-210 performs on the R2 and it wasnt shabby

ccp900 wrote in post #18542864
i have been toying with the idea of carrying a 10-18 for family travel photography paired with an FF body. Substantial benefit on weight but still have an 18MP file to work with.

i saw in the sony alpha camera group in facebook how the 55-210 performs on the R2 and it wasnt shabby

I've started using my 10-18 on my a9 quite a bit since making this thread. It's just as quick changing to it as it is busting out my a6500, and at the end of the day I don't have to upload two memory cards.

I tried my 18-35 sigma .. works every well.
Actually making me consider atleast some lenses in apsc. (Maybe )
But..
I thought file size would be smaller , but im still getting 80mb files.